Method of snap fitting channel members and foaming in place an interlock therebetween

ABSTRACT

The present method produces a structural unit, for instance a window frame, comprising heat conducting structural members and rigid connecting means therebetween, by clamping a hollow, resilient connecting element between said structural members and then filling the hollow resilient element with a hardenable mass which by its hardening eliminates the resiliency and thus provides said rigid connecting means. The connecting element may be of substantially H-shaped or rectangular cross section with means for engaging the structural members. The resiliency may be the natural resiliency of the material of which the connecting element is made.

United States Patent [191 Nipp METHOD OF SNAP FITTING CHANNEL MEMBERS AND FOAMING IN PLACE AN INTERLOCK THEREBETWEEN Inventor: Ernst Nipp, Georg-Wulf-Strasse 5, 28 Bremen 1, Germany [22] Filed: Feb. 22, 1971 [21] Appl. No.: 117,396

[30] Foreign Application Priority Data Mar. 6, 1970 Germany 2010663 July 27, 1970 Germany 2037081 [52] US. Cl 52/743, 52/731, 49/DIG. 1, 52/309 [51] Int. Cl. E04g 21/00, E04c 2/26 [58] Field of Search 52/730, 731, 309, 393, 52/403, 743, 282; 49/DIG. 1

[56] References Cited UNITED STATES PATENTS 3,014,611 12/1961 Marshall .1 52/272 3,517,472 6/1970 Toth 52/309 3,557,514 1/1971 Fahrni t 52/730 3,156,332 11/1964 Cameron 49/DIG. 1 3,451,183 6/1969 Lespagnol et al. 52/282 3,562,992 2/1971 Kinsey 52/731 FOREIGN PATENTS OR APPLICATIONS 2,005,438 12/1969 France..... 49/DIG. 1 1,489,331 6/1967 France 49/DIG. 1

356,265 9/1961 Switzerland 52/730 6,514,536 7/1966 Netherlands.... 49/DIG. 1 1,509,548 5/1969 Germany 52/731 Primary Examinefi-l-Ienry C. Sutherland Assistant Examiner.lames L. Ridgill, Jr. Attorney, Agemgor FirmW. G. Fasse 5 7 ABSTRACT The present method produces a structural unit, for instance a window frame, comprising heat conducting structural members and rigid connecting means therebetween, by clamping a hollow, resilient connecting element between said structural members and then filling the hollow resilient element with a hardenable mass which by its hardening eliminates the resiliency and thus provides said rigid connecting means. The

connecting element may be of substantially H-shaped or rectangular cross section with means for engaging the structural members. The resiliency may be the natural resiliency of the material of which the connecting element is made.

2 Claims, 13 Drawing Figures PATENTED MR 26 \974 SHEET 2 UF 3 PATENTEU MR2 6 I974 SHEU 3 OF 3 METHOD OF SNAP FITTING CHANNEL MEMBERS AND FOAMING IN PLACE AN INTERLOCK THEREBETWEEN BACKGROUND OF THE INVENTION The present invention relates to a method for producing a structural unit.-More specifically the invention relates to producing connections between heat conducting structural members, especially metal or steel structural members, whereby the connections are to be rigid, forcc transmitting, as well as heat insulating between said structural members which are subjected to relatively high temperature gradients.

Modern windows, for instance, comprise interconnected profile sections, including a first profile section facing the outside air and a second section facing the interior. Both members are interconnected by means of connecting elements made of a material with low heat conductivity, such as a synthetic material. The same insulating problems exist in connection with the steel structures of high-rise buildings, such as steel frame buildings. In such buildings flat steel profiles abut against the exterior wall of the building so as to be flush therewith and to be rigidly connected to a metal profile extending in the wall or along the interior surfaces of the wall.

It is known in the prior art to glue the connecting elements of synthetic material to the profile sections. However, in this manner a structural unit of sufficient durability or strength can not be obtained.

Furthermore, it is known to provide a serrated joint between the connecting elements and the profile sections or members. However, even these connections are not sufficiently strong. In connections with light metal profile sections it has been attempted to increase the strength of the connection by subsequently deforming the profiles in certain places along their length. Aside from the additional work involved in this procedure, the profile sections may be weakened to an undesirable degree.

OBJECTS OF THE INVENTION It is, therefore, an object of the present invention to I SUMMARY OF THE INVENTION In accordance with the present invention, one or more hollow, initially semi-rigid connecting elements are clamped in their proper position to the structural members to be joined. In this clamped position the connecting elements are subject to an elastically yielding force, for instance under the influence of the natural or inherent resiliency of the material of which the connecting elements are made. Thereafter, the hollow spaces in the semi-rigid connecting elements are filled with a hardenable material so that a force-transmitting rigid connection is created by eliminating said elastically yielding force.

The thus formed connection is undetachably locked. The two connected structural members, such as metal profile sections, form together with the usually longitudinally extending connecting element in the form of moldings of synthetic material a structural unit of high durability and strength which is resistant to bending and twisting and which has a high moment of inertia.

The above-mentioned hollow spaces in the connecting elements are preferably filled with a very tacky or adhesive synthetic foam comprising minute bubbles therein, for instance a polyurethane. Preferably, the foam is introduced into the hollow spaces under a pressure of approximately 2 kilograms per centimeter square (gauge).

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be clearly understood it will now be described, by way of example, with reference to the accompanying drawings:

FIG. 1 is a cross section through two metal profile sections constituting two structural members which are interconnected by a connection element in the form of a molding made of a material having a low heat conductivity;

FIG. 2 shows a section similar to that of FIG. 1 with a connecting element having a differing section structure as compared to that of FIG. 1;

FIGS. 3 and 3a show a modification wherein the connecting elements comprise a closed chamber to be filled with the hardenable material and with separated but overlapping walls in the area where interengaging means between the structural members and the connecting elements are provided;

FIGS. 4 and 4a are sections similar to those shown in FIGS. 3 and'3a, with a connecting element having a closed filling chamber but without overlapping end walls;

FIG. 5 represents a cross section through two connected window frames with each frame being subdivided in the plane of the window;

FIG. 6 is a partially sectional, perspective view of a connecting element'in accordance with the present invention and having an H-configuration with chambers which are open at the outer ends of the H-legs which are provided with engaging means;

FIG. 7 is a front view of a cover profile for a window frame;

FIGS. 8 and 9 respectively, represent sectional views taken along the lines A-A and BB of FIG. 7 on a larger scale than FIG. 7; and I FIGS. 10 and 11 are perspective views of a profile section of a connecting element adapted for use also as a structural member, and of a cover member preferably of steel sheet for said connecting element.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION FIGS. 1 and 2 show a structure comprising a profile member 1 made of light metal, a profile member 2, likewise made of light metal, and connected to profile 1 through an intermediate hollow connecting element 3 made of a relatively hard synthetic material. The ele ment 3 is provided with engaging means such as nose portions or protrusions 4 which engage in correspondingly shaped recesses in profile members 1 and 2 respectively. In order to be able to insert element 3 into these recesses while making use of the transverse resiliency of element 3, wall portions 5 and 6 of this hollow connecting element 3 are connected at the center thereof by a cross piece 7 of a relatively soft synthetic material. This central cross piece is adapted to elastically yield whereby the nose portions or protrusions 4 can be snapped into the grooves or recesses of the profile members 1 and 2 while simultaneously assuring an exact fit. When the two metal profile sections are exactly aligned with respect to each other for an exact fit, the hollow element 3 of synthetic material is filled under pressure, with a relatively quickly setting synthetic foam 9. The synthetic foam moves through the passage 8 in the wall shaped cross piece 7. This synthetic foam, which is preferably a polyurethane, has the property of intimately bonding itself to the adjacent structural members by adhering very well to the surfaces thereof.

A modification of the connection element 3 of FIG. 1 is shown in FIG. 2. There the outer walls 5 and 6 are interconnected by a central cross piece 10 made of a relatively stiff or rigid material so that the outer walls 5 and 6 together with cross piece 10 form a unit whereby the cross piece 10 also comprises a passage 8. With this embodiment it is necessary to press or bend toward each other the ends of the outer walls 5 and 6 which face the metal profiles or structural members 1, 2 in order to assure that the engaging means such as the protrusions or nose portions 4 engage in corresponding grooves or recesses in the profile members. This pressing or bending is possible due to the natural or inherent resiliency of the material of which the side walls 5 and 6 are made. The cross piece 10 in this example is made of rigid material so that it does not yield while the outer wall ends are bent inwardly. Here again the hollow space or chamber is filled with a foam material after the two profiles occupy their proper position and properly fit together whereby the foam material prevents the nose portions 4 from resiliently disengaging themselves from the grooves or recesses. Moreover, just as in the first embodiment, the foam material forms an intimate bond with the surfaces of the adjacent profiles or structural members 1 and 2 which form plane surfaces in the area of the grooves or protrusions.

Referring to FIGS. 3 and 3a, the connecting element 3a is likewise locked into grooves of the profile members 1a and 2a under the influence of its transverse resiliency. These figures also show that the connecting element may require a special shape or form where the structural members do not have plane abutting surfaces, for example, because thereare apertures 1b, 2b in the profile members la and 1b to be interconnected, to nevertheless have a closed filling chamber for the foam. As illustrated in FIGS. 3 and 3a, the connecting element 311 has at its ends facing the structural profile members 1a and lb resilient overlapping wall portions 11. The separated but overlapping wall portions, as illustrated in FIG. 3a, permit that the connecting element may yield transversely with the upper ends of its side walls 5 and 6 while the cross piece 10 with its passage 8 forms an unyielding intermediate abutment.

Still another modification according to the present invention is shown in FIGS. 4 and 4a. The connecting element 3b confines a closed chamber 3c with walls 5 and 6 similar to the embodiment described above.

However, the walls 12 and 13 which face the structural members are considerably thinner than walls 5 and 6. When pressing the member 3b in the direction of the arrows A shown in FIG. 4a, the wall 12 bends inwardly whereby this wall serves as a spring member for pressing the nose portions or protrusions 4 into their respective grooves or recesses in the profile member 1h. As described in connection with the previous embodiments, once the connecting element 3!) is snapped into place, the chamber 9 is filled with a foam material under pressure whereby the wall 12 become approximately straight. It has been found that the polyurethane foam brings about a small increase of the volume of the chamber by bulging the yielding chamber confining walls outwardly. The resulting pre-stress or bias tension has the advantage that upon hardening of the foam material the pressure is reduced somewhat while a disengagement of the interlocked nose portions and recesses does not result from later shrinkage of the foam material.

The arrangement according to FIG. 5 shows two interconnected window frames made of light metal profiles. The outer and inner profile portions 1c, 1d and 2c, 2d respectively are connected to each other by the connecting and heat insulating elements 3, which are open toward the profile members. These profile members 10 and 2c are provided with anchoring means, for example T-shaped anchoring elements 14 which extend into both chambers above and below the cross piece, which chambers are filled with synthetic foam. In this manner, the hardening foaming mass forms a very intimate bond and interconnection with the metal surfaces of the abutting profile members 1c, 20.

At least one of the two profile or structural members of each window frame comprises a rectangular hollow space or chamber 15, 16 extending longitudinally of the structural member but at right angles to the plane of the drawing of FIG. 5. One end face or wall of these hollow chambers 15, 16 abuts the engaging means of the connecting element 3. These rectangular hollow spaces 15, 16 form box-shaped beams l5, 16 which together with said connecting elements result in a window frame which is particularly resistant to bending and twisting or torsional forces and thus the present window frame has good strength characteristics, especially when used in a movable window frame or casement. FIG. 6 shows perspectively an embodiment of a connecting element 3d according to the present invention will engaging means comprising leg portions 4 laterally yielding, for use in connection with metal profile members having smooth abutting surfaces in the area of said leg portions 4. The inner walls 4 of the hollow space confined by this connecting element 3d taper inwardly toward the cross piece 10a whereby these inner walls of the filling chamber are closer to each other adjacent to the leg portions 4 than at the center of the walls. Incidentally, the space between interconnected structural units or said beams 15, 16 is suitable for inserting a miter angle in a well known manner.

The structural units according to the present invention are not only suitable for the described examples such as windows and doors in the outer walls of houses, but these units are also useful in any situation with similar or comparable conditions, where for instance inserts such as two-piece columns or posts are provided in outer walls of buildings, even in high-rise buildings. Furthermore, the invention is applicable to supports,

posts or the like used in light weight construction, which may not only be used as structural units when erecting buildings, but also as frames for relatively large and heavy glass sheets or panes, such as insulating glass in the outside wall of buildings. The present supports, posts, or structural units extend in the outside wall of buildings preferably within the window front and between adjacent windows vertically from floor to floor. Such structural units or frame profiles for large and heavy windows should have a relatively low weight, nevertheless they should be resistant to bending and especially against buckling.

For'reasons of strength, the present supports have to be made of profiled metal or even profiled thin-walled steel and it must be assured as much as possible that a temperature equalization between the outside and the inside of the respective wall is prevented. While adhering to the basic teaching underlying the present invention, it has been found to be advantageous to make the profile member or structural member facing the outside of the wall and the adjacent connecting element formed as a molding completely of synthetic material and in one piece.

Referring now specifically to FIGS. 7 to 11, the buckle and bending resistant frame profiles shown therein are intended for heavy window panes. The same profiles may also be used as supports for other purposes. The profile member 21 made of metal or, more specifically, of steel comprises substantially a box-like beam with the customary abutment moldings for the window. The profile member 22 is made of synthetic material and comprises two legs 23 protruding toward the profile member 21 for engaging with its marginal protrusions 24 into corresponding grooves of the profile member 21. After the two profile members have been fitted or snapped together, the inherent transverse yielding of the leg portions 23 is eliminated by injecting a hardenable synthetic material 25 through holes 26 into the chamber confined by the legs 23 whereby an unintentional disengagement of the protrusions 24 becomes impossible.

The disengagement of the two profile members, however; can also be prevented by providing a steel cover profile 27. This profile may be made of alloyed steel, for instance stainless steel, and slipped over or pressed upon the profile member 22 thereby enclosing the margins 28 and 29 of the profile member 21. The embodiment of the profile member 22 shown in FIG. has a marginal portion 28 provided with an inclined surface 32 whereby it is possible to press the cover profile 27 onto the profile member 22 transverse to its longitudinal extension even after member 27 encloses already the marginal portion 29 since the synthetic material of member 22 yields elastically. In order to neutralize the resiliency of the leg portions23, it is sufficient that the cover profile 27 snugly fits against the outside surface of the synthetic material profile 22 and surrounds or encloses the marginal portions of this profile 22. However, it is even better to provide a small pre-stress or biasing tension between members 22 and 27.

The shape of the integral profile, that is the combination of the profile members 21 and 22, is such that for purposes of inserting and fixably connecting a relatively heavy glass pane 30 of insulating glass, a framelike profile is produced in which a sealing mass 31 as shown in- FIGS. 8 and 9 is used.

In the embodiment illustrated in FIG. 10, the flat or plane face of the profile member 22 is bent somewhat outwardly in a direction transvers to the longitudinal extension of the member. In this way upon attachment of the plane cover profile member 27 the marginal portions 28 and 29 of profile member 22 are bent back substantially into one plane so that the two leg portions 23 with their protrusions 24 come to rest solidly in-the longitudinal grooves of the profile member 21 whereby an undesirable disengagement between the two members is prevented and an even more rigid engagement is assured.

Gluing of the cover profile member to the synthetic material profile member should, but not necessarily, be avoided since both members are made of rather different materials having different expansion coefficients.

The formation or shaping of the entire structural unit comprising the combination of the profile 21 with the profile 22 is such that a frame-like profile is produced for inserting and connecting a relatively heavy pane 30 of insulating glass whereby the sealing mass 31 is used as shown in FIGS. 8 and 9.

While preferred embodiments of the invention have been described and shown, it is to be understood that the invention is intended to cover any modifications and equivalents within the scope of the appended claims.

What I claim is:

1. In a method for producing a rigid structural unit including first heat conducting structural means having first connecting elements, second heat conducting structural means having second connecting elements, and a heat insulating connecting member providing a heat barrier between said first and second structural means and having further connecting elements engaged with respective ones of said first and second connecting elements of said first and second structural means to confine a hollow space therebetween which is then filled with a hardenable mass, the improvement comprising:

a. producing at least certain ones of said connecting elements as elastically yielding snap-in elements having a natural resiliency providing initially an elastically yielding biasing force;

b. elastically snapping said snap-in elements into engagement, whereby said hollow space is confined between the structural means and the connecting member;

0. filling said hollow space with said hardenable mass,

and

d. foaming and hardening said mass, said foaming and hardening eliminating said elastically yielding biasing force to form a rigid connection between the first and second structural means while maintaining said heat barrier.

2. In a method for producing a rigid structural unit including heat conducting structural means and heat insulating structural means, wherein both of said structural means include connecting elements for interengaging said structural means with each other to confine a hollow space therebetween which is then filled with a hardenable mass which together with said heat insulating structural means provide a heat barrier, the improvement comprising:

a. producing at least certain ones of said connecting elements as elastically yielding snap-in elements having a natural resiliency to provide initially an elastically yielding biasing force,

b. elastically snapping said snap-in elements into engagement whereby said hollow space is confined between the structural means;

(2. filling said hollow space with said hardenable mass,

and 

1. In a method for producing a rigid structural unit including first heat conducting structural means having first connecting elements, second heat conducting structural means having second connecting elements, and a heat insulating connecting member providing a heat barrier between said first and second structural means and having further connecting elements engAged with respective ones of said first and second connecting elements of said first and second structural means to confine a hollow space therebetween which is then filled with a hardenable mass, the improvement comprising: a. producing at least certain ones of said connecting elements as elastically yielding snap-in elements having a natural resiliency providing initially an elastically yielding biasing force; b. elastically snapping said snap-in elements into engagement, whereby said hollow space is confined between the structural means and the connecting member; c. filling said hollow space with said hardenable mass, and d. foaming and hardening said mass, said foaming and hardening eliminating said elastically yielding biasing force to form a rigid connection between the first and second structural means while maintaining said heat barrier.
 2. In a method for producing a rigid structural unit including heat conducting structural means and heat insulating structural means, wherein both of said structural means include connecting elements for interengaging said structural means with each other to confine a hollow space therebetween which is then filled with a hardenable mass which together with said heat insulating structural means provide a heat barrier, the improvement comprising: a. producing at least certain ones of said connecting elements as elastically yielding snap-in elements having a natural resiliency to provide initially an elastically yielding biasing force, b. elastically snapping said snap-in elements into engagement whereby said hollow space is confined between the structural means; c. filling said hollow space with said hardenable mass, and d. foaming and hardening said mass, said foaming and hardening eliminating said elastically yielding biasing force to form a rigid connection between the two structural means while maintaining said heat barrier. 